Review

New Roof Drains and Piping to Downpipe

Insert two new roof drain outlets to improve drainage on the butanol flat roof. Select an 80mm outlets and place about 400mm apart- use for example ALLPROOF VRTW80.88 new side outlet. The drain outlets should be placed approximately 10mm below the current top surface of inner gutter, flush with the bottom, below the current plywood surface. Position of the drains close to the low point of the butanol roof, approximately 1.9 m from the Northern study inner wall and 0.9m from the Western inner study wall. Piping to follow these dimensions and exit through the outer brick wall (.35 m ). See New Roof Drains Approximate Piping Design. Site visit suggested. The piping intended should be normal 80mm (RP80) piping, T joints (RJ80), connectors (RAS80) and 88 deg turns (RP80). Fitting should leave study against the existing study wall (3deg slant drop) and exit to outside, through the outer brick wall beside the down pipe. To ensure positive flow the pipe should end with 0.6m drop and T joint to the existing 80mm rain water downpipe. All pipe fittings should be strong enough to carry full weight and full flow pressure under storm conditions without risk of leaking or damage. Strong downward slope should ensure positive waterflow all through the piping, even with leaves, pine needles and other forest debris.